DIRECT MEMORY ACCESS UNIT AND COMMUNICATION SYSTEM, MOBILE RADIO AND DATA PROCESSING UNIT WITH THE DMA UNIT

摘要

The communication system (1) consists of a microprocessor (2), a direct memory access, DMA, unit (3), multiple serial interfaces (4a) as well as a bus controller that are all connected to a bus. The bus has a data bus (61) and an address bus (62). One of the serial interfaces (4a) has a control line coupled to the microprocessor via the DMA unit which has a linear buffer (15) and a ring buffer (16). The microprocessor has an interrupt control unit (11) that has a number of interrupt vectors.